carotenoid vs phytochemical

carotenoid and phytochemical both are nouns.

Word	Noun	Adjective	Verb	Adverb
carotenoid	Yes	No	No	No
phytochemical	Yes	No	No	No

As nouns, phytochemical is a hypernym of carotenoid; that is, phytochemical is a word with a broader meaning than carotenoid:

carotenoid: any of a class of highly unsaturated yellow to red pigments occurring in plants and animals
phytochemical: a chemical substance obtained from plants that is biologically active but not nutritive

Other hypernyms of carotenoid include antioxidant, pigment.

carotenoid (noun)	phytochemical (noun)
any of a class of highly unsaturated yellow to red pigments occurring in plants and animals	a chemical substance obtained from plants that is biologically active but not nutritive